Material interfaces are ubiquitous features on many types of devices. As a result, constant use of different materials must be considered to achieve specific functions within in the device. In order for some of these devices to function, various materials must be attached to one another. One common way of attachment is to use an adhesive.
The selection of a proper adhesive is dependent on many different factors, including the materials being joined together, curing time, bonding strength, final use of the product, among others. Each of these factors can limit the applicability of adhesives, especially if the adhesive is needed for a specific material or for a sensitive use. Depending on the particular factors, an adhesive may be ideally suited for one situation and may not be functional in another.
An important consideration in the efficacy and duration of an adhesive bond is the surface of the materials to be used. In some instances, surface preparation allows the adhesive to form bonds with the actual surface of the material and not to other substances or debris located on the material. Often, bonding is dependent on intermolecular interactions between the surface of the material and the adhesive. Given that different materials will have varying characteristics, however, the quality of bonding between an adhesive and two dissimilar materials may be very different.
A current limitation with many adhesive systems is a lack of control over the reaction rate which can lead to adhesives setting too rapidly or too slowly for optimal performance. When considering bonding of an adhesive to a surface the reaction must proceed at a rate which allows integration of surface functionalities into the bulk reaction of the adhesive. However, if the reaction proceeds too slowly micromotion may interfere with good surface bonding and/or unacceptable time may be needed before an interface can be functionally bonded.
In addition, adhesives used for medical devices must also consider the possible toxicity of the adhesive to humans and, if implantable, sterility and how the adhesive will react to the conditions within the human body. Medical devices have a wide range of possible applications which require adhesives, including but not limited to, diagnostic products, implants, surgical instruments, dental articles, among others. Recently, certain types of equipment, including items such as surgical instruments and catheters, have become reusable. The reusable nature of these types of products would subject any adhesives used in these devices to the process of cleaning and sterilization over repeated times.
There exists a need in the art for compositions and methods for bonding two materials in the preparation of a device (e.g., a medical device).